木村 優彌

PURPOSE: To assess how intraoperative macroscopical anterior cruciate ligament (ACL) findings affect perioperative procedures, biomarkers, and postoperative anterior-posterior (AP) laxity and range of motion (ROM) after cruciate-retaining (CR) total knee arthroplasty (TKA) and to determine how chronic ACL deficiency may affect postoperative inflammatory biomarker, AP laxity, and ROM. METHODS: A total of 121 patients with varus knee osteoarthritis without a history of ACL injury who underwent ATTUNE® (DePuy Synthes, Warsaw, IN) CR TKA were analyzed. Intraoperative ACL findings were stratified into intact, damaged, and diminished, according to the tension by probing, synovial coverage, and vascularity. C-reactive protein (CRP) levels were examined at one, seven, and 14 days after surgery. Knee AP laxity measurements using Kneelax 3 (Monitored Rehab Systems, Haarlem, The Netherlands) and postoperative knee ROM were also compared. RESULTS: One-way ANOVA showed significant differences in CRP levels examined one day after surgery observed between the three groups (8.4 (3.8), 9.8 (4.3), and 13.2 (7.7) mg/dL, respectively; P = 0.018), with post hoc analysis showing that CRP levels one day after surgery were significantly greater in the diminished group than in the intact and damaged groups (P = 0.012 and 0.023, respectively). AP laxity in 30° of knee flexion was observed between the three groups (5.4 (2.3), 5.8 (2.5), and 7.1 (2.8) mm, respectively; P = 0.039), with post hoc analysis showing that AP laxity in 30° of knee flexion was significantly greater in the diminished group than in the intact group (P = 0.038). Knee ROM showed no significant differences. CONCLUSION: Intraoperative ACL diminishment was associated with higher CRP one day after surgery and midrange AP laxity one year after surgery.

BACKGROUND: Total knee arthroplasty (TKA) alleviates pain and improves daily living activities in individuals with end-stage osteoarthritis of the knee. However, up to 20% of patients have sub-optimal outcomes after TKA. OBJECTIVE: No studies have clarified the intraoperative factors that affect postoperative range of motion (ROM) after cruciate-retaining (CR) TKA. Thus, this study aims to clarify these factors. METHODS: Patients with knee osteoarthritis with varus knee deformity who underwent CR-TKA between May 2019 and December 2020 were included in this study. One year after surgery, patients were stratified into two groups based on knee flexion: Group F (over 120∘) and Group NF (below 120∘). Patient backgrounds including age, body mass index, hip knee angle, preoperative range of motion for both extension and flexion, intraoperative center joint-gap measurements of 0∘, 30∘, 45∘, 60∘, 90∘, and 120∘ of knee flexion using a tensor, intraoperative anterior-posterior (AP) laxity measurements of 30∘ and 90∘ of knee flexion using an instrumental laximeter were compared between the groups. Univariate analyses between the groups were used to construct the initial model. The receiver operating characteristic curve was also analyzed. The predictive variables included in the final model were selected by stepwise backward elimination. RESULTS: Intraoperative AP laxity with 30∘ of knee flexion smaller than 10.8 mm was a significant positive prognostic factor (OR: 1.39, 95% CI: 1.08-1.79, P= 0.011) of postoperative ROM over 120∘ of knee flexion one year after surgery. The sensitivity, specificity, PPV, and NPV were 70.9%, 82.4%, 92.9%, and 46.7%, respectively. CONCLUSION: Intraoperative AP laxity smaller than 10.8 mm was a significant positive predictive factor for obtaining knee flexion greater than 120∘ one year after surgery when using CR-TKA and its PPV was high up to 92.9%.

Two elderly female patients with Kellgren-Lawrence grade 4 knee osteoarthritis (KOA) having varus knee deformity and retained hardware for internal fixation in either femur or tibia underwent total knee arthroplasty (TKA) using 3D templating and patient-specific instrumentation (PSI). TKA was performed to treat KOA by minimally removing or without removing the retained hardware for the internal fixation of distal femoral or tibial diaphyseal fractures. Throughout a 2-year follow-up period, no superficial or deep infection was observed. In additions, no radiological symptoms of suspected component loosening were observed. Furthermore, both patients can currently walk without using crutches. 3D templating and PSI in primary TKA for patients with retained hardware for internal fixation of femoral or tibial fractures are considered suitable treatment options for reducing surgical invasion.

High tibial osteotomy (HTO) is used in the treatment of varus knee osteoarthritis (KOA) in young and active patients. At times, a concomitant anterior cruciate ligament (ACL) deficiency is found, and there is no conclusive evidence comparing the osteotomy options for an ACL-deficient knee despite the popularity of medial opening-wedge (MOW) HTO in varus KOA with ACL deficiency. To minimize the incidence of an unnecessary ACL reconstruction with MOW-HTO, we developed an intraoperative laximetry-based selective technique for transtibial ACL reconstruction concomitant with MOW-HTO using a sterilizable metal laximeter. To successfully use the device required for this procedure, surgeons must understand the proper techniques. Hence, this Technical Note aims to give a comprehensive description of the technique.

INTRODUCTION: Arterial injury following total knee arthroplasty (TKA) can be life-threatening. There are some anatomical variations in the popliteal artery (PA) and its branches. In most cases, the PA branches into the anterior tibial artery (ATA) and posterior tibial artery (PTA), which are usually distal to the height of tibial resection in TKA. However, some cases show that the PA branches into the ATA and PTA proximal to the height of tibial resection in TKA. This study aimed to assess the distance from the posterior cortex of the proximal tibia to the anterior wall of the PA or ATA at the height of the tibial cut line, during TKA in the distal and proximal branch groups. METHODS: 129 patients (6 patients in the proximal branch group and 123 patients in the distal branch group) were enrolled for this study. For prediction of the distance from the posterior cortex of the proximal tibia to the anterior wall of the PA or ATA, preoperative sagittal and coronal magnetic resonance images and postoperative radiographs were evaluated. RESULTS: The distance between the posterior cortex of the proximal tibia and the anterior wall of the PA or ATA at the height of the tibial cut line was 1.8 ± 1.1 mm in the proximal branch group and 6.1 ± 2.6 mm in the distal branch group, which was significantly closer in the proximal group (P < .05). DISCUSSION: The rate of proximal branching was 4.7%. This study clarified that the proximal branching of the ATA from PA significantly decreased the distance between the posterior cortex of the proximal tibia and the anterior wall of the artery. CONCLUSIONS: The proximal branch group has a high risk for arterial injury as the artery may be close to the saw, and appropriate retraction should be performed.

BACKGROUND: Total knee arthroplasty (TKA) is a widely performed procedure to alleviate pain and restore function of patients with end-stage knee osteoarthritis. OBJECTIVE: The study aim was to determine if tibia-first (TF) total knee arthroplasty (TKA) using a novel computer-assisted surgery (CAS) system can yield better anterior and posterior (AP) knee stability. METHODS: Patients with knee osteoarthritis with obvious varus knee who met the indication for and underwent TKA from May 2019 to November 2020 were included. Forty-one measured resection (MR)-TKAs and 32 TF-TKAs were compared. The varus-valgus ligament balance and joint tension at a joint center-gap setting equal to the tibial-baseplate thickness were measured, and appropriate polyethylene inserts with 0∘, 30∘, 45∘, 60∘, 90∘, and 120∘ of knee flexion were placed. A Kneelax 3 arthrometer was used to measure knee AP laxity in the postoperative anesthetized patients with 30∘ and 90∘ of knee flexion. RESULTS: The horizontal gap balance was significantly closer in the TF-TKA group than the MR-TKA group for 0∘, 30∘, 45∘, and 60∘ of knee flexion. In contrast, no significant differences were observed for 90∘ and 120∘ of knee flexion. No significant differences in joint-gap tensions among all knee-flexion angles were observed. Translation was significantly smaller in the TF-TKA group than the MR-TKA group for AP laxity with 30∘ of knee flexion (8.8 ± 2.9 mm vs. 10.7 ± 3.1 mm, P= 0.0079). In contrast, no significant AP laxity was observed with 90∘ of knee flexion (7.2 ± 2.8 mm vs. 7.2 ± 3.5 mm). CONCLUSION: TF-TKA using a novel CAS system provided better AP knee stability with close to horizontal gap balances.

RATIONALE: Acute aortic occlusion is an uncommon disease with a high morbidity and high mortality. Clinical symptoms typically include acute lower limb pain, acute paralysis, and absent pulses. We report a very rare case of acute aortic occlusion causing complete paralysis of bilateral lower limbs following microendoscopic laminectomy. PATIENT CONCERNS: A 64-year-old man with hypertension, hyperlipidemia, diabetes, and atrial fibrillation underwent microendoscopic laminectomy for lumbar spinal stenosis. After the operation, intermittent claudication improved significantly without neurological deficit. However, 7 days later, he developed complete paralysis of the bilateral lower limbs, extreme pain of the bilateral lower limbs, and mottling of the left extremity. DIAGNOSIS: An emergency magnetic resonance imaging examination revealed no epidural hematoma behind the spinal cord, proscribing spinal cord compression. Computed tomography revealed occlusion of the infrarenal abdominal aorta. Blood tests revealed high values of total plasminogen activator inhibitor-1 before surgery. INTERVENTIONS: The acute aortic occlusion was verified and underwent thrombectomy and right axillary-bifemoral bypass. OUTCOMES: Following the revascularization, the neurological deficit of the lower limbs improved. On follow-up after 1 year, the muscle strength of the bilateral lower limbs had returned to normal. LESSONS: This case presentation highlights the necessity of early diagnosis and early revascularization. Moreover, a preoperative high value of plasminogen activator inhibitor-1 may indicate vascular complications including Acute Aortic Occlusion.